Psycholinguistics vs. socio-linguistics, ultimately rests on one question:

could people think without language? Unfortunately there’s no way to test the proposition, because, even if you could locate people who’ve never had language, how would you document their thought processes without language? Okay, so the logic is circular and forms a tautology, so more importantly, without begging the question of ‘thought’ itself: Is intelligence a function of language? Certainly you can’t penalize bears for improper vocal chords anymore than you can punish dolphins for lack of an opposable thumb, so you look for behavior that might indicate abstract thought regardless of any symbols that might suggest language. A ‘mental’ language should require no symbols; it is pure code. I see much behavior that promotes survival, but not much more than that. Furthermore, back to the original question, any animal capable of sound is capable of language, whether it be clicks or whistles, giggles or gurgles; the more complex, the better. I don’t see it, any more than I see primitive tribes building cities. Furthermore, there seems to be a clear correlation between complexity of language and complexity of civilization. Bird’s songs and bees’ dances aren’t language. Traveling long distances does not count as intelligence. All animals do that, for whatever reason, most likely to get to the other side. If there is no better measure of intelligence, then let it be complexity, in behavior and symbolism. Still other questions arise from the issue: Would it occur to people to invent language if they hadn’t already been taught it? Why do children learn language so easily and so fast, which is the psycholinguist’s ace in the hole? Answer: They don’t. I have a better question: Why do most adults learn so slowly?